Trauma, Shock, and Resuscitation
A 58-year-old woman is brought to the emergency department (ED) by emergency medical service (EMS) after slipping on a patch of ice while walking to work and hitting her head on the cement pavement. Bystanders acknowledged that the patient was unconscious for approximately 1 minute. On arrival, her vital signs are blood pressure (BP) 155/75 mm Hg, heart rate (HR) 89 beats/minute, respiratory rate (RR) 18 breaths/minute, and pulse oxygenation 98% on room air. She has a 5-cm laceration to the back of her head that is actively bleeding. You ask the patient what happened, but she cannot remember. You inform her that she is in the hospital as a result of a fall. Over the next 10 minutes, she asks you repeatedly what happened and where she is. You do not find any focal neurologic deficits. As you bring the patient to the computed tomography (CT) scanner, she vomits once. CT results show a normal brain scan. Which of the following is the most likely diagnosis?
d. Posttraumatic epilepsy
e. Trauma-induced Alzheimer disease
The answer is a. The patient sustained a cerebral concussion. This is caused by a head injury leading to a brief loss of neurologic function. These individuals are often amnestic to the event and frequently ask the same questions over and over again (perseveration). Headache with or without vomiting is generally present; however, there are no focal neurologic findings on examination. Loss of consciousness results from impairment of the reticular activating system (RAS). Patients show rapid clinical improvement. CT scan of the brain is normal.
Diffuse axonal injury (b) is the result of microscopic shearing of brain nerve fibers. Patients typically present unconscious and remain in a coma for a prolonged period of time. Initial CT scan is often insensitive for diffuse axonal injury and may lead to a false negative diagnosis. Patients with diffuse axonal injury have over a 33% mortality rate. The clinical features of a cerebral contusion (c) are similar to those of a concussion except that neurologic dysfunction is more profound and prolonged. Focal deficits may be present if contusion occurs in the sensorimotor area. Contusions occur when the brain impacts the skull and the lesion is typically seen on CT scan. Posttraumatic epilepsy (d) is associated with intracranial hematomas and depressed skull fractures. The seizures generally occur within the first week of the head injury. Some scientists believe that head trauma predisposes to Alzheimer disease (e); however, this would take years to develop.
A 41-year-old restrained driver involved in a high-speed motor ...